In conventional OMVPE reactors, single ended gas injection schemes are typically used to distribute the gas flow across susceptors. Due to their inability to create a laminar gas flow across a wide cross-section distance, the resultant epilayer uniformity in the direction perpendicular to the gas flow direction is not as good as that in the direction parallel to the gas flow direction. Furthermore, the lack of uniformity also restricts the size of the wafers on which epilayers can be grown. In the evolution of processing equipment for device and integrated circuit fabrication, the ability of handling larger wafer sizes has continuously expanded to enable increased product output or throughput. OMPVE technology has become important in the fabrication of microwave and optoelectronic device applications.
A gas distribution arrangement is required for providing an extremely uniform gas flow across a wide distance perpendicular to the gas flow if epilayer uniformity in the direction perpendicular to the gas flow direction is to be as good as that in the direction parallel to gas flow direction. This characteristic is particularly important for scaling up of horizontal type OMVPE reactors and would also be useful for vertical type OMVPE reactors for improving their uniformity of the deposited epilayer.